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United States Patent |
5,069,108
|
Dion
|
December 3, 1991
|
Blasting device for unblocking mine raises
Abstract
A blasting device for unblocking ore passes, backfill raises, mine draw
points and any other near vertical raises where rocks or other materials
normally fall freely but may get blocked during use, comprises a
propulsion unit including an air chamber mounted at the end of a hollow
tube and having an inlet for receiving pressurized air and at least one
outlet for allowing compressed air jets to exit downwardly from the air
chamber to propel the propulsion unit upwardly, a reservoir mounted on the
propulsion unit and adapted to hold explosive and an igniter, means for
feeding pressurized air into the air chamber through the hollow tube, and
an ignition line connected to the igniter for igniting the explosive from
a distance.
Inventors:
|
Dion; Serge (856 Boul D'Alembert, D'Alembert, Quebec,, CA)
|
Appl. No.:
|
668268 |
Filed:
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March 11, 1991 |
Foreign Application Priority Data
Current U.S. Class: |
86/20.15; 89/1.34; 299/13 |
Intern'l Class: |
F42D 003/04; F42B 003/00 |
Field of Search: |
299/13
175/2
86/20.15
89/1.34
102/301,375,319,504
|
References Cited
U.S. Patent Documents
2818809 | Jan., 1958 | Roy | 86/20.
|
3541797 | Nov., 1970 | Stewart | 86/20.
|
3770523 | Nov., 1973 | Biswas | 86/20.
|
4036099 | Jul., 1977 | French | 86/20.
|
4040329 | Aug., 1977 | Ljungberg | 86/20.
|
4522125 | Jun., 1985 | Marz | 299/13.
|
5007345 | Apr., 1991 | Garr | 86/20.
|
Primary Examiner: Brown; David H.
Attorney, Agent or Firm: Fleit, Jacobson, Cohn, Price, Holman & Stern
Claims
I claim:
1. A blasting device for unblocking ore passes, backfill raises, mine draw
points and any other near vertical raises where rocks or other materials
normally fall freely but may get blocked during use, comprising:
a) a propulsion unit including an air chamber mounted at the end of a
hollow tube and having an inlet for receiving pressurized air and at least
one outlet for allowing compressed air jets to exit downwardly from said
air chamber to propel the propulsion unit upwardly;
b) a reservoir mounted on said propulsion unit and adapted to hold
explosive and an igniter;
c) means for feeding pressurized air into said air chamber through said
hollow tube; and
d) an ignition line connected to said igniter for igniting said explosive
from a distance.
2. A blasting device as defined in claim 1, further comprising a plurality
of radial rods mounted circumferentially on said blasting device to keep
the blasting device away from the walls of the raise thus allowing the
device to raise freely along the walls of the raise.
3. A blasting device as defined in claim 1, further comprising a plurality
of fins equally spaced around said tube for allowing aiming of the device
at a particular blockage point and movement of the blasting device towards
the blockage point under the thrust of compressed air.
Description
This invention relates to a blasting device for unblocking ore passes,
backfill raises, mine draw points or any other near vertical raises, where
rock or other material fall freely, but which may get blocked during use.
Ore passes, backfill raises, mine draw points or any other near vertical
raises often get blocked during use and it is always a problem to unblock
them as it is highly unsafe for a miner to work in the vicinity of and
more particularly underneath a blockage area. It is common practice to
unblock mine raises by attaching explosive sticks at the upper end of a
string of poles, bracing the lower end of the string at the base of the
raise and igniting the explosive to blast the rock blockage. However,
working in the area immediately adjacent to the base of a raise is
generally dangerous. Thus, some raises are never unblocked and this result
in great losses in the mines.
It is the object of the present invention to provide a device for
unblocking mine raises which presents a minimum of exposure for the
miners.
The blasting device, in accordance with the present invention, comprises a
propulsion unit including an air chamber mounted at the end of a hollow
tube and having an inlet for receiving pressurized air and at least one
outlet for allowing compressed air jets to exit downwardly from the air
chamber to propel the propulsion unit upwardly, a reservoir mounted on the
propulsion unit and adapted to hold explosive and an igniter, means for
feeding pressurized air into the air chamber through the hollow tube, and
an ignition line connected to the igniter for igniting the explosive.
A plurality of radial rods are preferably mounted circumferentially around
the blasting device to keep sensitive points of the blasting device away
from the walls of the raise and thus allow the device to raise freely
along the walls of the raise.
A plurality of fins may be equally spaced around the tube to allow aiming
of the device at a particular blockage point when such blockage is in a
line of sight and movement of the blasting device towards the blockage
point under the thrust of compressed air.
The invention will now be disclosed, by way of example, with reference to
the accompanying drawings in which:
FIG. 1 is a diagram of a raise having a rock or other material blockage at
an intermediate point;
FIG. 2 is a side view of a blasting device in accordance with the present
invention;
FIG. 3 is a section view of the blasting device of FIG. 1; and
FIG. 4 is a view of an alternative embodiment of a blasting device in
accordance with the present invention.
Referring to FIG. 1, there is shown a diagram of a raise 10 having a rock
blockage area at an intermediate point 11. To loosen the rocks, a blasting
device designated generally by reference numeral 12 is allowed to climb up
the walls of the raise under the thrust of compressed air generally
provided in a mine and be blasted to free the rocks.
The blasting device is shown more clearly in FIGS. 2 and 3 and comprises a
propulsion unit 14 comprising an air chamber mounted at the end of a
hollow tube 16 which acts as a stabilizer and through which is fed
compressed air from a hose 18 as shown in FIG. 1. The air chamber has a
plurality of equally spaced air outlets 20 for allowing air jets to exit
downwardly to provide an upward thrust to the propulsion unit. A reservoir
22 is mounted on the propulsion unit for containing explosive and a
suitable igniter for the explosive. As shown in FIG. 1, an ignition line
24 is connected to the igniter and is allowed to hang down to the bottom
of the raise for ignition when the blasting device is in place. A
plurality of radial rods 26 made of non-conductive material are equally
spaced around the circumference of the device to keep the blasting device
away from the walls of the raise and thus allow the device to climb freely
along the walls of the raise.
In operation, the hollow tube 16 of the blasting device is connected to the
hose 18 and the hose is itself connected to a compressed air supply 28.
Compressed air is fed through the hollow tube and the air jets from the
outlets 20 of the propulsion unit exert an upward thrust to cause the unit
to move up along the walls of the raise until it contacts the rock
blockage. The ignition line is ignited and the explosive blasted to
unblock the raise.
In order to allow the blasting device to raise under the regular 100 psi.
air pressure normally provided in the mines, the blasting device is
normally made of light but strong plastic materials which are commercially
available.
FIG. 4 illustrates an alternative embodiment of a blasting device similar
to the one shown in FIG. 2 which is provided with equally spaced fins 30
around the hollow tube 16. This allows the device to be aimed at a
particular blockage point when such point is in a line of sight. The
blasting device then moves towards the target point under the propelling
action of compressed air.
Although the invention has been disclosed with reference to a preferred
embodiment, it is to be understood that it is not limited to such
embodiment and that other alternative are also envisaged within the scope
of the following claims.
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